The association between the RAGE G82S polymorphism, sRAGE and chronic periodontitis in Taiwanese individuals with and without diabetes.

BACKGROUND AND OBJECTIVE: The present study investigated the association between the RAGE G82S polymorphism, the plasma levels of sRAGE and chronic periodontitis in subjects with and without diabetes mellitus (DM). MATERIAL AND METHODS: A total of 230 patients with DM and 264 non-DM participants were recruited for this study. Genotyping of the RAGE G82S polymorphism was accomplished using polymerase chain reaction-restriction fragment length polymorphism, and associations were analyzed with the chi-squared test and logistic regression analysis. RESULTS: In the non-DM group, the chi-squared test showed that the frequency distributions of the G82S polymorphism were significantly different between chronic periodontitis and non-chronic periodontitis subjects (chi(2) = 8.39, p = 0.02). A multivariate logistic regression model showed that the (G82S + S82S) genotypes were associated with a significantly increased risk of chronic periodontitis development compared to the G82G genotype (adjusted odds ratio = 2.06, 95% confidence interval: 1.08-4.07). In the DM group, there was no association between the G82S polymorphism and chronic periodontitis development when a multivariate logistic regression was performed. Plasma levels of sRAGE were significantly higher in subjects with the G82G genotype compared to those with the (G82S + S82S) genotypes in both the non-DM (856.6 +/- 332.0 vs. 720.4 +/- 311.4 pg/mL, p = 0.003) and DM groups (915.3 +/- 497.1 vs. 603.5 +/- 298.3 pg/mL, p < 0.0001). However, there was no difference in plasma sRAGE levels between chronic periodontitis and non-chronic periodontitis subjects in both the DM and non-DM groups. Moreover, when the subjects were further sub-divided by the G82S polymorphism, the difference in plasma levels of sRAGE between chronic periodontitis and non-chronic periodontitis subjects in the DM and non-DM groups remained statistically insignificant. CONCLUSIONS: The present study revealed that the RAGE G82S polymorphism was associated with chronic periodontitis in the non-DM group but not in the DM group. Our results also showed that the plasma levels of sRAGE were significantly higher in subjects with the RAGE G82G genotype, and this correlation was not affected by the presence of chronic periodontitis in the DM and non-DM groups.